1. Field of the Invention
This invention generally relates to a radar system and, more particularly, to improvements in a target tracking radar system.
2. Description of the Prior Art
In each conventional, prior art, monopulse radar system, used for ground target tracking, reliance is placed on beam patterns in sum and difference channels. These patterns represent energy which is reflected by a particular target. The patterns are processed frequency wise with respect to a frequency which is associated with the target in order to position or align the antenna so that it points accurately, toward the target. Such a target tracking technique can only be used if the required tracking accuracy is not great and/or if the reflected energy versus noise from the target, i.e., the signal-to-noise ratio is high. If, however, a weak target has to be tracked, the noise in the system, including thermal noise, may nearly obliterate the weak signals from the target so that accurate tracking becomes impossible.
If a larger area, around the target, is accepted in order to increase the signal-to-noise ratio, then, variations of backscatter amplitude with azimuth angle affects target azimuth angle pointing. Weak return signals and high tracking accuracy characterize most airborne tracking radar system, designed to track a ground target. Thus, a need exists for improvements in a monopulse-type target tracking radar system, particularly of the airborne type, designed to track a ground target.